Etiology of Periodontal Disease

Current Model
1. Plaque Biofilm
  1. Often leads to gingival inflammation
    1. Quite often leads to Perio Pocket formation
      1. ... factors may contribute to...
        Immunological response
        Microflora
        Systemic conditions
        genetics
        Smoking
        non-plaque related local factors
      2. sometimes leads to progression of periodontitis
        Occlusal trauma may
        Less often: loss of teeth
  2. Evidence
    1. Experimental gingivitis in man Loe, Theilade and Jensen 1965
      1. The effect of a preventive programme on plaque, gingivitis and caries in school children. Axelsson and lindhe 1974
        effects of controlled oral hygiene procedures on caries and perio disease in adults. Axelsson and lindhe 1978
        Natural history of perio disease. Loe 1986
        shows that plaque is a factor in periodontal disease
        effective OH supplemented by professional therapy prevents perio disease and controls caries
      2. evidence that plaque causes gingival inflammation
        because withdrawal of OH -> plaque accumulation -> gingivitis (10-21 days)
      3. gingivitis is reversible
        bcos reinstitution of OH -> resolution of gingival inflammation in 7 days
  3. plaque retentive factors affect
Primary etiological factor = PLAQUE
1. Socransky et al 1998
  1. Subgingival plaque formation: successive wave of colonization by increasingly periopathogenic clusters of bacteira
    1. shifts from gram +ve to gram -ve
2. Primary goal of periodontal therap
  1. preserve the natural dentition by achieving and maintaining a healthy functional periodontium
    1. OHI and patient motivation
    2. mechanical removal of supra and subgingival plaque and calculus deposits
    3. Correction of risk factors
      1. Plaque retentive factors
3. Plaque
  1. a mass of microorganisms and their products which colonize the surfaces of teeth, dental restorations, gingival sulcus and periodontal pockets
4. Biofilm
  1. a microbial community enveloped by extracellular biopolymer which these microbial cells produce, that adheres to the interface of a liquid and a surface
  2. How does the BIOFILM FORM
    1. PELLICLE FORMATION
      1. TRANSPORTATION
        AGGREGATION
        CO-AGGREGATION
        DETACHMENT
        allows colonization at new sites
        occurs by
        shear forces
        active detachment
        environmental cues
        of new bacteria to already attached bacteria: Fusobacterium Nucleatum acts as a bridge between
        early colonizers
        later colonizers that do not attach to early colonizers
        STAGES
        Initial
        van der Waal's
        hydrogen bond
        Later
        covalent bond
        ionic bond
        electrostatic
        Irreversible
        Binding of adhesins (on bacterial surfaces) to specific receptors (on acquired pellicle)
        Mutans Streptococci: Glucan binding protein to Glucan
        Streptococcus spp: lipotechoic acid (LTA) to Glycopreoteins
        Actinomyces Naeslundii: Type 1 Fimbriae to Proline-rich proteins
        Primary colonizers
        Actinomyces
        Oral Strep
        of bacteria to pellicle via
        salivary flow
        brownian motion
        chemotaxis
      2. Acquired pellicle to tooth surface
  3. PROBLEMS WITH BIOFILMS!
    1. Ability to colonize
    2. cause direct tissue damage (potent collagenase)
    3. evade host defences (ineffective neutrophil phagocytosis)
    4. resistant to anti-microbial compounds
      1. Slow growing
      2. EPS - slow penetration
      3. resistant phenotype
        enzme degradation
        Efflux pump
      4. communication
        quorum sensing
        metabolic
        gene transfer
5. Extracellular polymeric substrances
  1. consists of a wide variety of
    1. glycoproteins
    2. proteins
    3. glycolipids
    4. extracellular DNA
  2. Functions
    1. highly hydrated and form a a matrix
      1. keeps the biofilm together
    2. Provide nutrients for biofilm organisms
      1. absorptive properties sequester dissolved and particulate substances from environment
    3. attaches the biofilm to surfaces
CONTRIBUTING FACTORS
1. Plaque retention factors
  1. Calculus
  2. Iatrogenic factors
    1. Margins of restoration
    2. Materials
    3. retained cement, peri-implantitis
    4. RD procedures
    5. Design of RPD
    6. Contours, open contacts
    7. wisdom tooth surgery
    8. habits and self-inflicted injuries
    9. Ortho
  3. Anatomy
    1. Malocclusion
    2. Furcation
    3. Root trunk length
    4. size of furcation entrance
    5. Bifrucation ridges
    6. root concavity
    7. CEP
    8. enamel pearls
    9. multiple roots
    10. grooves
2. Systemic factors
3. Smoking
4. Non-plaque related local factors
  1. Lichen Planus
  2. Herpetic lesions
  3. Pemphigoid
  4. Streptococcal infection

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Etiology of Periodontal Disease

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	Created by Eryn Chan about 9 years ago